Seroprevalence and risk factors associated with bovine leukemia virus (BLV) seropositivity in cattle herds from Ecuador


  • Luis R. Saa Private Technical University of Loja
  • Lucía T. Guzmán Private Technical University of Loja
  • Natacha C. Fierro Private Technical University of Loja
  • Luz M. Castro Private Technical University of Loja
  • Fabián Reyes-Bueno Private Technical University of Loja
  • Alfonso Carbonero University of Córdoba



BLV, bovine leukemia virus, cattle, cows, EBL, enzootic bovine leukosis, epidemiology, prevalence, risk factors, ruminant, seroprevalence, seropositivity, virus


Background: Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL). This disease mainly affects cattle, causing severe economic losses to producers. Objective: To establish individual and herd seroprevalence and determine the risk factors associated with BLV seropositivity for dairy and dual-purpose cattle herds in Ecuador. Methods: A total of 2,668 serum samples from 386 herds were collected. A questionnaire, including variables related to cattle health, management and the environment was completed by each herd. A commercial blocking enzyme-linked immunosorbent assay (ELISA) test was used to determine seropositivity. A generalized estimating equation model (GEE) was developed to determine the factors associated with BLV seropositivity. Results: Individual seroprevalence of BLV infection in Ecuador was 17.3% (CI95% = 15.86-18.74%). Herd prevalence was 37.8% (CI95% = 33.0-42.6%), and intra-herd prevalence ranged between 12.5 and 100% (median: 37.5%). The risk factors associated with BLV seropositivity were artificial insemination (OR: 2,215; CI95% = 1.402-3.501), concrete floors (OR: 2.178; CI95% = 1.217-3.889), presence of wild ruminants (OR: 2.998; CI95% = 1.788-5.027), and sampling season (wet; OR: 1.996; CI95% = 1.140-3.497). Conclusions: Results indicate that BLV is widespread in cattle herds in Ecuador. In addition, the study suggests that a control program to fight BLV infection should focus on controlling the risk factors identified.

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How to Cite

Saa, L. R., Guzmán, L. T., Fierro, N. C., Castro, L. M., Reyes-Bueno, F., & Carbonero, A. (2020). Seroprevalence and risk factors associated with bovine leukemia virus (BLV) seropositivity in cattle herds from Ecuador. Revista Colombiana De Ciencias Pecuarias, 34(3), 177–188.



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